You may already know that are three main “states”
of matter: gases, liquids, and solids (there are
really four, but that is besides the point). Your
question is asking which solids undergo the
solid-to-gas transition, sublimation.
Whether or not a solid will sublime depends on a
number of factors. Sometimes, a solid will favor
going to the liquid state before the gaseous state
and other times a chemical reaction will occur
before the temperature can be raised high enough
to get the original molecules in the gas state.
There is a subject called thermodynamics that
allows us to find the temperatures at which solids
will turn into liquids and gases and the
temperatures at which chemical reaction can occur.
If a chemical reaction does not occur and the
liquid state is not favored over the gas state as
you raise the temperature, the solid will sublime.
Consider a couple of solids: ice, which is made
out of water molecules, dry ice, made from carbon
dioxide molecules, and wood, made from cellulose
First, imagine we take a piece of ice and set
it outside on a sunny day. We notice that the ice
begins to melt and eventually all we have left is
a pool of water. If we wait even longer we see
that the pool of water has disappeared.
Essentially, ice prefers to change into the
liquid state first before evaporating into the
gaseous state. (*Note this is not completely true!
Even ice and snow sublime to a certain extent
before changing in the liquid state!)
Now imagine we take a piece of dry ice and lay it
outside on a sunny day. If you’re not sure what
dry ice is, you might want to youtube dry ice. In
this case we see that the dry ice begins to
vaporize directly from the solid state!
Finally, we lay the wood outside on a sunny day.
Nothing happens of course and, being the
scientists we are, we decide that we must heat the
wood even more to try to make it into a gas.
However, as soon we heat the wood, for instance
with a match or a lighter, we see that the wood
catches fire. This is an example of a chemical
reaction, where cellulose molecules in the wood
and actually being converted into among other
things, carbon dioxide, the stuff of dry ice and
what we breathe out.
Examples of solids that sublime are dry ice
(solid carbon dioxide), iodine, arsenic, and
naphthalene (the stuff mothballs are made of).
This is a great question that is more difficult to
answer than you would suspect. If you are
interested in learning more, please free to ask.
Any solid may be sublimed if its temperature and
pressure are below its triple point. For example,
if you were to freeze water into ice and cool it
further and then reduce the pressure, you could
get ice to sublime. Some other examples include:
Dry ice (solid CO2) which sublimes at atmospheric
pressure and -78 C, and C60 (buckyballs) which
sublimes at atmospheric pressure at around 800 K.
Some common solids go through sublimation at
standard pressure (1 atmosphere). Carbon dioxide
sublimates at -78.5 °C (-109.3 °F), and we use
this “dry ice” for cooling purposes. Iodine is
another substance that has been observed to
sublimate at room temperature and pressure.
Naphthalene, a chemical with numerous
applications, sublimates at approximately 80 °C
(176 °F). A substance which normally doesn’t
sublimate (i.e. water) at standard pressure can be
made to sublimate at lower pressures. The phase
relationships of a chemical are expressed on a
phase diagram with pressure and temperature as the
A number of solids are capable of sublimating at
normal temperatures and pressures, including snow,
iodine, arsenic, and solid carbon dioxide (dry
ice). Sometimes other materials can be made to
sublimate by creating low pressure conditions.
If you take a materials science class in the
future (probably in college), then you will learn
to read "phase diagrams," which are basically
graphs that show what temperatures and pressures
are required to have solid, liquid or gas phases
for a material. You can see from these diagrams
whether or not there is an available transition
directly from solid to gas for any material. This
tells you whether or not a material is capable of
Almost all solids can go through sublimation,
under certain conditions. This just means the
solids go straight to gasses without becoming
liquids first. Typically solids undergo
sublimation at low pressures (under vacuum). At
standard, atmospheric pressure, a few solids which
will sublime are iodine (at slightly higher than
room temperature), carbon dioxide (dry ice) at
-78.5 degrees Celsius, as well as naphthalene
(used in mothballs) and arsenic.